Supply hopper for delicate, rod-shaped products, in particular in cigarette packaging machines

Abstract: Supply hopper for delicate, rod-shaped products, in particular in cigarette packaging machines, which hopper (1) is provided in its lower part with a plurality of separate discharge channels (2), each of which is divided by means of intermediate walls (4) into several ducts (3) which are vertical and parallel to one another, in each of which ducts (3) there is formed at least one substantially vertical row of cigarettes (S) which are superimposed on one another, whereas above the upper end (104) of each intermediate wall (4) there is provided a roller (6) which is horizontal and parallel to the axis of the cigarettes (S) in the hopper (1), and is rotated, preferably with oscillatory motion. According to the invention, in order to prevent to a large extent the formation of bridges of cigarettes which block the ducts (3), the rollers (6) are disposed quincuncially relative to a horizontal plane, i.e. they are alternately offset parallel to one another upwards and downwards.

Description: The invention relates to a supply hopper, in particular in cigarette packaging machines, which hopper is provided in its lower part with a plurality of separate discharge channels, each of which is divided by means of intermediate walls into several ducts which are vertical and parallel to one another, in each of which ducts there is formed at least one substantially vertical row of rod-shaped products which are superimposed on one another, whereas above the upper end of each intermediate wall there is provided a roller which is horizontal and parallel to the axes of the rod-shaped products in the hopper and is rotated with oscillatory motion, the rollers being disposed alternately offset to one another upwards and downwards, relatively to an horizontal plane and, the relative offsetting of the axes of the rollers corresponds substantially to approximately half the diameter of the rod-shaped products, or to an order of magnitude of that type, while the free transverse gap between two adjacent rollers and the width of the duct beneath, at least in the mouth area, are smaller than twice the diameter of a rod-shaped product and larger than the diameter of a rod-shaped product, and preferably approximately one and a half times the diameter of a rod-shaped product. A hopper of this type is known from the document FR-A-2 372085, in which the staggered rollers have a circular cross-section. From the document US-A-3 435940 a similar hopper is known, in which the rollers have a polygonal cross-section, but are aligned with their axes in the same horizontal plane. In these known hoppers, the rollers transmit their rotary motion to the cigarettes in such a degree, that the rotation of the cigarettes around their own axis can cause the tobacco to come out from the ends of the cigarettes, so to empty partially the cigarettes and to contribute to the formation of faulty products. The object of the invention is to provide a hopper of the type initially described and defined in the pre-characterizing part of claim 1, and in which , owing to relatively single and inexpensive means, the rod-shaped products are subjected to a considerably reduced rotation about their own axis. To this end the hopper according to the invention is characterized in that the rollers have a polygonal transverse cross-section and are oscillated in both directions around a predetermined median position, in which the upper surface of the roller is substantially horizontal and constitutes a support surface for the rod-shaped product above, while the amplitude of oscillation in both directions is such that in each extreme oscillation position, the said upper support surface is in a substantially vertical position. Thus each cigarette which is supported on a roller is tilted in a position of alignment with the upper mouth of the corresponding duct beneath, without interfering negatively, in the sense of reciprocal wedging, with the adjacent cigarettes, and without undergoing rotational movements around its own axis, which could cause damage, and in particular emptying. According to a particularly advantageous embodiment, the rollers have a square transverse cross-section. In this case, the rollers oscillate by 90° clockwise and 90° anticlockwise, whereas they are disposed such that in the median angular position between the two extreme oscillation positions, and in the said two extreme oscillation positions, the roller has two vertical sides and two horizontal sides. A preferred embodiment of the hopper according to the invention is described with more details in the following description and is illustrated in the drawings, in which: Figure 1 is a front view of a supply hopper according to the invention in a cigarette packaging machine; Figure 2 is an enlarged lateral view, in partial cross-section, of a detail of a roller and the drive means thereof; Figures 3 to 6 show schematically various operative stages of the hopper rollers according to the preceding figures, during clockwise oscillation; and Figures 1 and 2 show a cigarette supply hopper in a cigarette packaging machine. On its lower side, the hopper 1 has three separate supply channels 2, each of which is subdivided by means of intermediate walls 4 into a specific number of substantially vertical ducts 3. Each channel 2 supplies a number of cigarettes S which corresponds to the number of ducts 3 on a collection plane 5, such that on the said plane 5 there is formed a row of cigarettes which are adjacent to one another transversely to their axis, which row is then transferred axially, together with a row of cigarettes associated with each of the subsequent two channels 2, into a collection cradle (not shown) of the packaging machine. The cigarettes S are accommodated in the hopper 1, with their axes oriented horizontally and parallel to one another. The ducts 3 of each channel 2 are slightly larger than the diameter of a cigarette, and thus each accommodates a substantially vertical row consisting of individual cigarettes S superimposed on one another. The intermediate walls 4 end substantially at the upper end of the corresponding channel 2. In particular, the upper ends 104 of the intermediate walls 4 end at levels which are offset alternately upwards and downwards relative to a horizontal plane. Above the upper head 104 of each intermediate wall 4 there is a roller 6. The rollers 6 are disposed at a slight distance from the opposite heads 104 of the intermediate walls 4, such that they can be rotated freely around their axis without interfering with the intermediate walls 4, and are oriented with their axes parallel to the axes of the cigarettes S. The rollers 6 have a transverse cross-section which is not round, and in particular is square, and have dimensions which are approximately those of the cigarettes S. In particular, the length of the diagonal of the rollers 6 corresponds substantially to the width of the upper head 104 of the intermediate walls 4 and to the diameter of the cigarettes. The rollers 6 are also disposed alternately offset to one another upwards and downwards relatively to a horizontal plane corresponding to the heads 104 of the intermediate walls. As can be seen in Figure 2, the rollers 6 are supported in a projecting manner in the hopper 1, and have a rear axial extension 106 which is supported such that it can be rotated by means of bearings 7 in part of the frame of the hopper. The axial extension 106 supports a pinion 206 in a manner such that it does not rotate reciprocally, which pinion engages with a rack 8. The rack 8 is oriented horizontally and transversely to the rollers 6, and is supported such as to slide longitudinally, in both directions, on lower guide rollers 9 which can rotate freely. The pinions 206 of both rollers 6 engage with two racks 8, which are activated with oscillatory linear motion by means of a motor and a drive, not shown in detail. It will be appreciated that other rotary means of driving the rollers 6 can be used, which can be of any type, and can consist of cams, lever systems or the like. With reference to Figure 3 in particular, the width of the mouth opening of the ducts 3, at least in the mouth area, and the distance between the opposite surfaces of the rollers 6 is larger than, or approximately one and a half times, the diameter of the cigarettes, but less than twice the diameter of the cigarettes. By this means, no more than one cigarette at a time can enter the ducts 3. With reference to the present embodiment, for a cigarette diameter of 8 mm, the following geometric arrangement is particularly efficient: distance between two adjacent rollers 16.5 mm; side of the square rollers 6 mm; reciprocal offsetting horizontally between two adjacent rollers of approximately at least half the length of the side, or half the length of the diagonal of the rollers 6. The rollers 6 are all oscillated in phase with one another, in both directions around an intermediate position, such that the upper sides 306 and lower sides 406 thereof are horizontal. The amplitude of oscillation is such that in the extreme oscillation positions clockwise and anticlockwise, the upper and lower sides 306, 406 of the rollers 6 are substantially vertical. In this case, since the rollers 6 have a square cross-section, the amplitude of oscillation is 90° clockwise and 90° anticlockwise, relative to the said intermediate position. Figures 3 to 6 illustrate respectively the intermediate oscillation position of some rollers 6, and three successive intermediate stages of oscillation thereof clockwise. As is also apparent from Figure 1, the natural arrangement of the cigarettes S in the area of the hopper 1 above the channels 2 is staggered. The staggered arrangement of the rollers 6 with the above-described distances apart substantially harmonizes with and corresponds to that of the cigarettes S. The upper side 306 of each roller 6 in the intermediate oscillation position, and in this case in the two extreme oscillation positions, constitutes a support surface for a single cigarette S' (Figure 3). During rotation of the rollers 6, the cigarette S' is tilted by the surface 306 into a position which coincides with the mouth of the associated duct 3 beneath. The staggered arrangement of the rollers 6 and the width of the mouth opening, which at least is less than twice the diameter of the cigarettes, prevents the cigarettes S from interfering with the cigarette S' and with the rollers 6, which would cause mutual wedging and thus form a bridge preventing access to the duct 3 by the cigarette S' and the cigarettes above. In addition, movement of the cigarettes which interfere with the rollers 6 is such as to give rise to a large extent only to translation, thus preventing movements of the cigarettes, and in particular rotation around their own axis which could give rise to emptying.

Claims: Supply hopper for delicate, rod-shaped products, in particular in cigarette packaging machines, which hopper (1) is provided in its lower part with a plurality of separate discharge channels (2), each of which is divided by means of intermediate walls (4) into several ducts (3) which are vertical and parallel to one another, in each of which ducts (3) there is formed at least one substantially vertical row of rod-shaped products (S) which are superimposed on one another, whereas above the upper end (104) of each intermediate wall (4) there is provided a roller (6) which is horizontal and parallel to the axis of the rod-shaped products (S) in the hopper (1) and is rotated with oscillatory motion, the rollers (6) being disposed alternately offset to one another upwards and downwards, relatively to an horizontal plane and, in the relative offsetting of the axes of the rollers (6) corresponds substantially to approximately half the diameter of the rod-shaped products (S), or to an order of magnitude of that type, while the free transverse gap between two adjacent rollers (6) and the width of the duct (3) beneath, at least in the mouth area, are smaller than twice the diameter of a rod-shaped product and larger than the diameter of a rod-shaped product, and preferably approximately one and a half times the diameter of a rod-shaped product, characterized in that the rollers (6) have a polygonal transverse cross-section and are oscillated in both directions around a predetermined median position, in which the upper surface (306) of the roller (6) is substantially horizontal and constitutes a support surface for the rod-shaped product above, while, the amplitude of oscillation in both directions is such that in each extreme oscillation position, the said upper support surface (306) is in a substantially vertical position, Hopper according to claim 1, characterized in that the rollers (6) have a square transverse cross-section. Hopper according to claims 1 and 2, characterized in that the oscillation performed by the rollers (6) is 90° clockwise and 90° anticlockwise, whereas the rollers are disposed such that in the median angular position between the two extreme oscillation positions, and in the said two extreme oscillation positions, the roller (6) has two vertical sides and two horizontal sides (306, 406). Hopper according to claim 2 or claim 3, characterized in that the transverse cross-section of the rollers (6) is approximately that of the rod-shaped products. Hopper according to any one of claims 2 to 4, characterized in that the rollers (6) have sides 6 mm long, a distance between rollers of 16.5 mm, and reciprocal offsetting of 3 to 4 mm. Hopper according to one of the preceding claims, characterized in that the upper ends (104) of the intermediate walls (4) are disposed alternately offset to one another upwards and downwards relatively to an horizontal plane, similarly to the associated rollers (6).

Inventors: SPADA VALTER, TOSI GIUSEPPE, SPADA, VALTER, TOSI, GIUSEPPE
Applicants: SASIB SPA, SASIB S.P.A.
Application year: 1994
Main classification: B65B19
IPC codes: B65B19